I wouldn't say all Italian neighborhoods are disappearing albeit most are,for example I was born in the Bronx, Throggs Neck to be precise,which is probablely,sadly,the most far gone of the five Boroughs and although my family for the most part left the BX you still have Italian enclaves all along the east bronx, It's not all about the "American Dream" but as a 21 year old "Kid" as my friend and fellow Bronx guy PB puts it, I'd pick my two floor house in Lower Westchester over a dirty tenement on 117th and Pleasent circa 1950,it's all about moving up the monetary ladder from immigrant to naturalized,just my perspective